I've always liked 'The Anniversary', the nearest Hammer ever got to Pinter. Adapted from a successful play, the film throws Bette Davis a huge psycho biddy bone as Mrs. MacTaggart, a one eyed widow and Mum from Hell who takes the annual opportunity of her Wedding Anniversary to gather her remaining family together and treat them like shit.
Her three sons are, respectively, a pervert, a wimp, and a cocky twat, and she pulls every trick in the book to jerk their strings, using emotional (and financial) blackmail to thwart any plans they might have to live normal lives away from her. She's a monster, and Davis was born to play her (it's hard to think of any other actress who could wring so much from the line 'Shirley, my dear, would you mind sitting somewhere else? Body odour offends me').
As well as Davis, the film has a great cast of British character actors, including Sheila Hancock, Annette Andre, the under rated Jack Hedley and the always brilliant James Cossins, playing an Arnold Layne type character who has a compulsion to steal ladies underwear from washing lines but, because he's basically very nice, pegs ten pound notes up as compensation.